Field-magnet coil for electrical machines.



PATENTED DEC. 22, 1903.

L. A. OSBORNE.

FIELD MAGNET COIL FOE ELECTRICAL MACHINES.

APPLICATION FILED JUNE 24, 1903.

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PATENTED DEC. 22, 1903.

L. A. OSBORNE. FIELD MAGNET COIL FOR ELECTRICAL MACHINES.

APPLICATION FILED JUNE 24, 1903.

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UNITED STATES Patented December 22, 1903.

PATENT OFFICE.

LOYALL A. OSBORNE, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO VEST-INGHOUSE ELECTRIC 85 MANUFACTURING COMPANY, A CORPORATION OFPENNSYLVANIA.

FIELD-MAGNET COIL FOR ELECTRICAL MACHINES.

{SPECIFICATION forming part of Letters Patent No. 747,631, dated D mb22, 1903.

Application filed June 24, 1903. Serial No. 162,907. (No model.)

To all whom it may concern:

Be it known that I, LOYALL A. OSBO RNE,

a citizen of the United States, and a resident of Pittsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in Field-Magnet Coils for Electrical Machines, ofwhich the following is a specification.

My invention relates to the field-magnets m of electrical machines, andparticularly to means for insulating and protecting the-coils of suchfield-magnets.

The object of my invention is to provide field-magnet coils with suchinsulating and r5 protecting means as shall effectively prevent anybreaking down of the structure by reason of heat and which shall alsoexclude moisture from the coil and prevent mechanical injury thereof.

My invention is primarily intended for use in connection with motorsutilized for propelling railway-vehicles; but it is susceptible of usein other relations, and any illustration or description which may bespecific to railway-motor construction is not intended to limit theinvention to such machines, but merely to set forth one specific meansof utilizing the same.

It is well known that conductors which are utilized to carry heavycurrents are heated by such currents and that such heat can beeffectively dissipated only by the circulation around and between thecoils or turns of the coils of currents of cooling fluid.

In the case of certain machines-such, for example, as railway-motors-itis generally impracticable to provide a circulation of air or liquid tokeep down the temperature on account of the practical necessity ofinclos- 4o ing the windings in order to protectthem from moisture andother atmospheric conditions. It is to such electrical machines that myinvention is specially applicable, and in order to keep down thetemperature as much as 5 possible I prefer to form the coils ofstrapcopper, thus insuring a maximum cross-section of conductor in agiven space, and thus minimize the resistance. The strap-copper may bebent either flatwise or edgewise; but

as certain advantages are to be found in the so edgewise construction Ihave illustrated this in the drawings.

My invention is illustrated in the accompanying drawings, in whichFigure 1 is a view, partially in end elevation and partially in section,of a portion of a field-magnet, showing one pole-piece and a coilmounted thereon. Fig. 2 is a view, partially in bottom plan andpartially in section, of the coil shown in Fig. 1. Fig. 3 is a view, ()0partially in plan and partially in section, of a portion of a coilhaving a modified form of casing. Fig. 4: is an end elevation of thecoil shown in Fig. 3, and Figs. 5 and 6 are detail views of a part ofthe casing shown in Figs. 6 3 and 4:.

Referring now particularly to Figs. 1 and 2, the coil 1 is formed of astrap conductor wound on edge in two separate and approximatelyconcentric sections 2 and 3, which are 7c connected together to operateas a single coil.

It is to be understood that anynumber of concentric coils may beemployed and that the strap conductors may be wound flatwise instead ofedgewise, if desired. Between adjacent turns of each coil are placedstrips 4 of shellacked asbestos or other heat-resisting insulatingmaterial, and the coils are baked under heavy pressure after being thusbuilt up. Between and around the coil-sections 2 and 3 are placed sheets5 of builtup mica or other suitable non combustible insulating materialof the proper thickness, these partitions and sheaths being formed of asmany parts as the size and form of the coils may require. The entirecoil thus built up and insulated is inclosed in a metal shell 6 and istightly wedged therein by means of mica and asbestos. The joints of thevarious parts of shell 6 are soldered or otherwise so sealed as to bemoisture-proof.

The ends 7 and S of the coil-sections 2 and 3 are respectively bentaround the ends of the leads 9 and 10, and the latter extend outwardthroughsuitablechambers11,whichareother- 5 Wise filled with suitableinsulating and moisture-excluding material 12. The complete coil ismounted upon a pole-piece 13, constituting part of a field-magnet frame14, which may be formed of either cast-iron or steel.

Although the coil shown in the drawings is designed for a railway-motorfield-magnet, it is to be understood that the same construction may beadopted in any type of field-magnet coil without departing from myinvention.

In the form of coiland casing shown in Figs. 3 to 6 the ends 7 and 8 ofthe coil project from the body of the casing 6 at the middle of one endand are attached to the corresponding leads 9 and 10 within aterminal-box 11, the cover 15 of which is anchored to the body part bymeans of a dovetail projection 16, the edges of which engagecorresponding undercut portions 17 of the body part.

It is seen from the drawings and the foregoing description that thepeculiar insulation precludes any possibility of roasting or burning outof the coils, that moisture is effectivelyexcludedbyahermetically-sealed shell, and that said shell also provides superiorprotection from mechanical injury.

I claim as my invention- 1. A field-magnet coil for electrical machinesformed of strap-copper and sheets of heat-resisting insulation betweenadjacent turns, in combination with a hermeticallysealed shell in whichsaid coil is inclosed.

2. In an electrical machine, a field-magnet coil having adjacent turnsseparated by heatresisting, insulating material and formed in twosections each of which is surrounded by sheets of heat-resisting,insulating material and a hermetically-sealed metal casing in which saidcoil is inclosed.

3. A field-magnet coil for electrical machines, comprising twoconcentric sections each formed of edgewise-bent, copper-strap, sheetsof insulating and heat-resisting material between adjacent turns, shellsof insulating and heat-resisting material surrounding the two sectionsof the coil and a hermeticallysealed metal shell in which said coil isinclosed.

4. A coil for electrical machines comprising a plurality of parts,insulating, heat-resisting material surrounding and separating saidparts and a hermetically-sealed metal shell in which said coil isinclosed.

5. A field-magnet coil for electrical machines having adjacent turnsseparated by insulating, heat-resisting material and a sheath ofheat-resisting, insulating material therefor and an inclosing metalshell having sealed joints.

6. A field-magnet coil for electrical machines comprising a plurality ofseparately-insulated parts and a hermetically-sealed metal shell inwhich said coil is inclosed.

7. Acoil forelectrical machines comprising a plurality of parts,insulating, heat-resisting material separating and surrounding saidparts and a hermetically-sealed metal shell for said coil having atwo-part terminal-box at one end.

8. Acoil for electrical machines comprising a plurality of parts,insulating, heat-resisting material separating and surrounding saidparts and a hermetically-sealed metal shell for said coil having aterminal-box atone end the cover of which has a removable dovetailconnection with the body portion.

In testimony whereof I have hereunto subscribed my name this llth day ofJune, 1903.

LOYALL A. OSBORNE.

Witnesses:

A. W. MONTGOMERY, BIRNEY HINES.

